In rendering of a visual image, the direction and intensity of the illumination are generally important considerations in the effect of the image on the person viewing the image. The direction, intensity and variation in lighting across an image may effect such things as the mood of the viewer in viewing the image and may also tend to high-light certain aspects of the image which are of artistic importance in the rendering of the image.
In making a motion picture, for example, a scene may be recorded several times, with the scene being illuminated from a number of diverse directions each time it is recorded. During the editing process, the director may select one of the recorded scenes to be put into the final motion picture. In some instances, the director may determine that none of the scenes are acceptable, and have to assemble the cast and retake the scene with appropriate lighting. In any case, such additional effort to take one scene can be an expensive and time-consuming process.
Similarly, a still photographer may take a number of photographs of a person or an object, with the illumination being provided from a number of directions. After the photographs are printed, the photographer may select one or several prints which are most pleasing to him or her, or which achieves the lighting effect which he or she wishes to have in the photograph. If none of the prints have the visual effects desired by the photographer, he or she may attempt to "touch up" one or several to attempt to reach the desired effects, or if possible to take additional photographs, all of which can be an expensive and time-consuming process.